1. Field of the Invention
The present invention relates to an apparatus for adjusting a tilt of a disc, and more particularly to an apparatus for easily adjusting a tilt of a disc which is loaded on a turn table of a disk recording/reproducing device and rotated at high speed.
2. Description of the Related Art
In general, a disc is used as a recording medium for recording information on, and reproducing information therefrom and leg, spiral or concentric tracks which contain the information. The information recorded on the disc is reproduced using a pick-up feeding means including a motor and a plurality of gear trains which are driven and rotated by the motor, and an optical pick-up device which is linearly moved by the pick-up feeding means in a radial direction of the disc.
A guide device for guiding an optical pick-up device which is moved along the radial direction of a disc D (not shown) is shown in FIG. 1. The guide device includes two guide shafts 12 and 12' which are fixed to a deck base 10 to be parallel with a horizontal axis of the optical pick-up device by bushes 14. A pick-up base 16 on which the optical pick-up device is mounted, is movably coupled to guide shafts 12 and 12'.
Supporting members 18 such as bosses and the like, protrude from on upper surface of the deck base 10 to support disc rotating means shown in FIGS. 1 and 2 for rotating the disc D at a linear velocity. The disc rotaing means includes a turn table 20 on which a nonmagnetic portion of the disc D rests, and a spindle motor 22 rotating shaft. An upper portion of the rotating shaft is coupled to the turn table 20.
The spindle motor 22 is fixed to a bracket 24 which contacts upper surface of supporting members 18, and the bracket 24 is fixed to the supporting members 18 by three fixing screws 28 to be spaced apart and fastened to the deck base 10. The bracket 24 is formed with two position setting holes 24a into which position setting pins 10a are respectively inserted.
The conventional disc rotating means constructed as above is fixed to the deck base 10 and operates as follows. First, the disc rotating means is mounted to the deck base 10 by which position setting pins 10a are inserted into the respective position setting holes 24a which protroded from the deck base 10. Then, the bracket 24 is fixed to the deck base 10 by means of the coupling fixing screws 28 with supporting members 18. The fixing screws 28 are arranged at a predetermined angle with respect to each other. At this time, the bracket 24 supports the spindle motor 22 and the turn table 20 coupled to the spindle motor 22 by contacting the upper portions the supporting members 18.
After this, the disc D is loaded on the upper surface of the turn table 20 and is rotatiled at a high velocity by rotating the power of the spindle motor 22. At the same time, a pick-up base 16 moves in a radial direction of the disc D along the guide shafts 12, 12' which are fixed to be parallel with the horizontal shaft of the optical pick-up device so that the optical pick-up device records the information on recording pits and/or reproduces the information therefrom.
In the conventional disc rotating device, however, since the bracket on which the spindle motor is mounted is fixed to the upper portion of the supporting member using a plurality of fixing screws, the contact are of the supporting members is small so that the supporting members cannot properly horizontally support the bracket. As a result the disc on the turn table is undesirably tilted. Moreover, since there is no a tilt adjusting means for adjusting the radial and tangential tilt of tile disc, the laser beam emitted from the optical pick-up device cannot accurately be focused on the record pits on the disc.